Storing files in blocks within composite images

A computer system, comprising:

• a processor system;
• and
• a computer storage media that stores computer-executable instructions that are executable by the processor system to at least:
• determine to replace a first file of a filesystem volume that is contained within a composite image (CIM) with a second file, the filesystem volume defining a first directory hierarchy;
• identify a first file definition within a metadata portion of the CIM, the first file definition defining first data of the first file as including a first data block of a first region file of the CIM that comprises a first plurality of equally-sized data blocks;
• and
• replacing the first file with the second file within the CIM, including:
• adding a second region file to the CIM that comprises a second plurality of equally-sized data blocks, including writing a portion of data from the second file into a second data block of the second region file;
• replacing the first file definition with a second file definition within the metadata portion of the CIM, the second file definition:
• defining second data of the second file as including the first data block within the first region file of the CIM, and
• defining the second data of the second file as also including the second data block of the second region file of the CIM;
• and
• incrementing a reference count associated with the second data block;
• wherein the second file definition replaces the first file definition within the metadata portion of the CIM, and the CIM after the replacement embodies a second directory hierarchy that is the same as the first directory hierarchy.

A computer storage medium that stores computer-executable instructions that are executable by a processor system to at least:

• determine to replace a first file of a filesystem volume that is contained within a composite image (CIM) with a second file, the filesystem volume defining a first directory hierarchy;
• identify a first file definition within a metadata portion of the CIM, the first file definition defining first data of the first file as including a first data block of a first region file of the CIM that comprises a first plurality of equally-sized data blocks;
• and
• replacing the first file with the second file within the CIM, including:
• adding a second region file to the CIM that comprises a second plurality of equally-sized data blocks, including writing a portion of data from the second file into a second data block of the second region file;
• writing a second file definition to the metadata portion of the CIM, the second file definition:
• defining second data of the second file as including the first data block within the first region file of the CIM, and
• defining the second data of the second file as also including the second data block of the second region file of the CIM;
• and
• incrementing a reference count for the second data block;
• wherein the second file definition replaces the first file definition within the metadata portion of the CIM, and the CIM after the replacement embodies a second directory hierarchy that is the same as the first directory hierarchy.